Field of the Invention
Various aspects of the present invention relate to an oxygen sensor, and more particularly, to an apparatus and a method for controlling an oxygen sensor capable of performing a diagnosis for detecting a non-behavior of the oxygen sensor.
Description of Related Art
In the typical engine driving apparatus, a fuel pump delivers fuel in a tank up to an injector through a fuel hose when an engine starts and an engine control device drives the injector to inject the fuel. The injected fuel is combusted and then exhaust gas is discharged.
An example of an apparatus which measures an oxygen concentration of the exhaust gas may include an oxygen sensor. The oxygen sensor is installed at a predetermined position of an exhaust manifold. Therefore, the oxygen sensor measures an oxygen ratio in the exhaust gas and notifies an electronic control module (ECM) of the measured oxygen ratio. In this case, the electronic control module (ECM) controls the injector depending on the oxygen ratio to control an air fuel ratio of a mixer which enters the engine.
Further, a resistance value inside the oxygen sensor which reacts to an oxygen amount in the exhaust gas varies depending on a temperature of the sensor. However, since the lower the temperature, the larger the resistance value, a magnitude in an output voltage of the oxygen sensor is reduced. When the magnitude in the output voltage is reduced, the electronic control module (ECM) may not properly distinguish a change in the oxygen amount in the exhaust gas.
Therefore, to keep the temperature of the oxygen sensor constant even in a region in which a temperature of the exhaust gas is low, the ECM controls the heater installed inside the oxygen sensor according to the temperature of the exhaust gas to keep the temperature of the sensor constant.
In this case, when heater performance is reduced and thus the oxygen sensor does not keep a constant temperature, the ECM performs only a fault diagnosis of the oxygen sensor based on a magnitude in internal resistance of the oxygen sensor.
In this case, for the fault diagnosis, it is detected whether the oxygen sensor is out of order based on exhaust gas modeling. The method requires an operation technology which requires much time and/or costs to determine whether the oxygen sensor is out of order.
Further, if it is determined that the oxygen sensor is out of order, the oxygen sensor is replaced by a new product, and therefore there is no room for improving the performance of the oxygen sensor.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.